/Engine/Source/Runtime/Landscape/Classes/LandscapeComponent.h
Generate mipmaps for height and tangent data.
void GenerateHeightmapMips ( [TArray](API\Runtime\Core\Containers\TArray)< [FColor](API\Runtime\Core\Math\FColor) * > & HeightmapTextureMipData, int32 ComponentX1, int32 ComponentY1, int32 ComponentX2, int32 ComponentY2, [FLandscapeTextureDataInfo](API\Runtime\Landscape\FLandscapeTextureDataInfo) * TextureDataInfo )